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Abstract:

Golf balls consisting of a dual core and a dual cover are disclosed. The
dual core consists of an inner core layer formed from a rubber
composition and an outer core layer formed from a highly neutralized
polymer composition.

Claims:

1. A golf ball consisting essentially of: an inner core layer formed from
a rubber composition and having a diameter of from 0.500 inches to 1.125
inches, a center hardness (Hcenter) of 45 Shore C or greater, and an
outer surface hardness of 60 Shore C or greater; an outer core layer
formed from a highly neutralized polymer composition and having an outer
surface hardness (Houter core) of 75 Shore C or greater; an inner
cover layer formed from a thermoplastic composition and having a material
hardness (Hinner cover) less than the outer surface hardness of the
outer core layer; and an outer cover layer formed from a composition
selected from the group consisting of polyurethanes, polyureas, and
copolymers and blends thereof.

14. A golf ball consisting essentially of: an inner core layer formed
from a rubber composition and having a diameter of from 0.500 inches to
1.125 inches, a center hardness (Hcenter) of 45 Shore C or greater,
and an outer surface hardness of 60 Shore C or greater; an outer core
layer formed from a highly neutralized polymer composition and having an
outer surface hardness (Houter core) of 75 Shore C or greater; an
inner cover layer formed from a thermoplastic composition and having a
material hardness (Hinner cover) of from 80 Shore C to 95 Shore C;
and an outer cover layer formed from a composition selected from the
group consisting of polyurethanes, polyureas, and copolymers and blends
thereof.

15. The golf ball of claim 14, wherein the diameter of the inner core
layer is from 0.850 inches to 1.125 inches.

16. The golf ball of claim 14, wherein the diameter of the inner core
layer is from 0.875 inches to 1.125 inches.

19. A golf ball comprising: a core consisting of: an inner core layer
formed from a rubber composition and having a diameter of from 0.850
inches to 1.150 inches, a center hardness (Hcenter) of from 50 Shore
C to 75 Shore C, and an outer surface hardness of from 60 Shore C to 85
Shore C; and an outer core layer formed from a highly neutralized polymer
composition and having an outer surface hardness (Houter core) of
from 80 Shore C to 95 Shore C; and a cover consisting of: an inner cover
layer formed from a thermoplastic composition and having a material
hardness (Hinner cover) of from 80 Shore C to 95 Shore C; and an
outer cover layer formed from a composition selected from the group
consisting of polyurethanes, polyureas, and copolymers and blends
thereof.

20. The golf ball of claim 19, wherein the diameter of the inner core
layer is from 0.875 inches to 1.125 inches.

23. The golf ball of claim 19, wherein the core has an overall dual core
compression of from 75 to 95.

24. The golf ball of claim 19, wherein the core has an overall dual core
diameter of from 1.520 inches to 1.590 inches.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent application Ser.
No. 12/233,792, filed Sep. 19, 2008, which is a continuation-in-part of
U.S. patent application Ser. No. 12/048,021, filed Mar. 13, 2008, which
is a continuation-in-part of U.S. patent application Ser. No. 11/767,070,
filed Jun. 22, 2007, which is a continuation-in-part of U.S. patent
application Ser. No. 10/773,906, filed Feb. 6, 2004, now U.S. Pat. No.
7,255,656, which is a continuation-in-part of U.S. patent application
Ser. No. 10/341,574, filed Jan. 13, 2003, now U.S. Pat. No. 6,852,044,
which is a continuation-in-part of U.S. patent application Ser. No.
10/002,641, filed Nov. 28, 2001, now U.S. Pat. No. 6,547,677. The entire
disclosure of each of these references is hereby incorporated herein by
reference.

FIELD OF THE INVENTION

[0002] The present invention generally relates to golf balls, and more
particularly to golf balls having dual cores surrounded by dual covers,
wherein the outer surface hardness of the outer core layer is greater
than the material hardness of the inner cover layer.

BACKGROUND OF THE INVENTION

[0003] Numerous golf balls having a multilayer construction wherein the
core hardness and cover hardness have been variously improved are
disclosed in the prior art. For example, U.S. Pat. No. 6,987,159 to Iwami
discloses a solid golf ball with a solid core and a polyurethane cover,
wherein the difference in Shore D hardness between a center portion and a
surface portion of the solid core is at least 15, the polyurethane cover
has a thickness (t) of not more than 1.0 mm and is formed from a cured
urethane composition having a Shore D hardness (D) of from 35 to 60, and
a product of t and D ranges from 10 to 45.

[0004] U.S. Pat. No. 7,175,542 to Watanabe et al. discloses a multi-piece
solid golf ball composed of a multilayer core having at least an inner
core layer and an outer core layer, one or more cover layers which
enclose the core, and numerous dimples formed on a surface of the cover
layer. The golf ball is characterized in that the following hardness
conditions are satisfied: (1) (JIS-C hardness of cover)-(JIS-C hardness
at center of core)≧27, (2) 23≦(JIS-C hardness at surface of
core)-(JIS-C hardness at center of core)≦40, and (3)
0.50≦[(deflection amount of entire core)/(deflection amount of
inner core layer)]≦0.75.

[0005] U.S. Pat. No. 6,679,791 to Watanabe discloses a multi-piece golf
ball which includes a rubbery elastic core, a cover having a plurality of
dimples on the surface thereof, and at least one intermediate layer
between the core and the cover. The intermediate layer is composed of a
resin material which is harder than the cover. The elastic core has a
hardness which gradually increases radially outward from the center to
the surface thereof. The center and surface of the elastic core have a
hardness difference of at least 18 JIS-C hardness units.

[0006] U.S. Pat. No. 5,782,707 to Yamagishi et al. discloses a three-piece
solid golf ball consisting of a solid core, an intermediate layer, and a
cover, wherein the hardness is measured by a JIS-C scale hardness meter,
the core center hardness is up to 75 degrees, the core surface hardness
is up to 85 degrees, the core surface hardness is higher than the core
center hardness by 8 to 20 degrees, the intermediate layer hardness is
higher than the core surface hardness by at least 5 degrees, and the
cover hardness is lower than the intermediate layer hardness by at least
5 degrees.

[0007] Additional examples can be found, for example, in U.S. Pat. No.
6,686,436 to Iwami, U.S. Pat. No. 6,786,836 to Higuchi et al., U.S. Pat.
No. 7,086,969 to Higuchi et al., U.S. Pat. No. 7,153,224 to Higuchi et
al., and U.S. Pat. No. 7,226,367 to Higuchi et al.

[0009] In one embodiment, the present invention is directed to a golf ball
consisting of an inner core layer, an outer core layer, an inner cover
layer, and an outer cover layer. The inner core layer is formed from a
rubber composition and has a diameter of from 0.750 inches to 1.190
inches, a center hardness (Hcenter) of 50 Shore C or greater, and an
outer surface hardness of 65 Shore C or greater. The outer core layer is
formed from a highly neutralized polymer composition and has an outer
surface hardness (Houter core) of 75 Shore C or greater. The inner
cover layer is formed from a thermoplastic composition and has a material
hardness (Hinner cover) less than the outer surface hardness of the
outer core layer. The outer cover layer is formed from a composition
selected from the group consisting of polyurethanes, polyureas, and
copolymers and blends thereof.

[0010] In another embodiment, the present invention is directed to a golf
ball comprising a core and a cover. The core consists of an inner core
layer and an outer core layer. The inner core layer is formed from a
rubber composition and has a diameter of from 0.750 inches to 1.190
inches, a center hardness (Hcenter) of from 50 Shore C to 70 Shore
C, and an outer surface hardness of from 60 Shore C to 85 Shore C. The
outer core layer is formed from a highly neutralized polymer composition
and has an outer surface hardness (Houter core) of from 80 Shore C
to 95 Shore C. The cover consists of an inner cover layer and an outer
cover layer. The inner cover layer is formed from a thermoplastic
composition and has a material hardness (Hinner cover) less than the
outer surface hardness of the outer core layer. The outer cover layer is
formed from a composition selected from the group consisting of
polyurethanes, polyureas, and copolymers and blends thereof.

DETAILED DESCRIPTION

[0011] A golf ball having a dual core (i.e., two-layer core) and a dual
cover (i.e., two-layer cover) enclosing the core is disclosed. The dual
core consists of an inner core layer and an outer core layer. The inner
core layer has a diameter within a range having a lower limit of 0.500 or
0.750 or 0.850 or 0.875 or 0.900 or 0.950 or 1.000 inches and an upper
limit of 1.125 or 1.150 or 1.190 inches. The outer core layer encloses
the inner core layer such that the two-layer core has an overall diameter
within a range having a lower limit of 1.400 or 1.500 or 1.510 or 1.520
or 1.525 inches and an upper limit of 1.540 or 1.550 or 1.555 or 1.560 or
1.590 inches. In a particular embodiment, the inner core layer has a
diameter of 1.000 inches and the outer core layer encloses the inner core
layer such that the two-layer core has an overall diameter of 1.530
inches or 1.550 inches.

[0012] The inner core layer has a center hardness (Hcenter) of 45
Shore C or greater, or 50 Shore C or greater, or 55 Shore C or greater,
or 60 Shore C or greater, or a center hardness within a range having a
lower limit of 40 or 45 or 50 or 55 or 60 Shore C and an upper limit of
65 or 70 or 75 or 80 Shore C. The inner core layer has an outer surface
hardness of 65 Shore C or greater, or 70 Shore C or greater, or 75 Shore
C or greater, or 80 Shore C or greater, or an outer surface hardness
within a range having a lower limit of 55 or 60 or 65 or 70 or 75 Shore C
and an upper limit of 80 or 85 or 90 Shore C. In a particular embodiment,
the Shore C hardness of the inner core layer's outer surface is greater
than or equal to the center Shore C hardness. In another particular
embodiment, the inner core layer has a positive hardness gradient wherein
the Shore C hardness of the inner core layer's outer surface is at least
10 Shore C units greater, or at least 15 Shore C units greater, or 19
Shore C units greater than the center Shore C hardness.

[0013] The outer core layer has an outer surface hardness (Houter
core) of 75 Shore C or greater, or 80 Shore C or greater, or greater than
80 Shore C, or 85 Shore C or greater, or greater than 85 Shore C, or 87
Shore C or greater, or greater than 87 Shore C, or 89 Shore C or greater,
or greater than 89 Shore C, or 90 Shore C or greater, or greater than 90
Shore C, or an outer surface hardness within a range having a lower limit
of 75 or 80 or 85 Shore C and an upper limit of 90 or 95 Shore C. In a
particular embodiment, the overall dual core has a positive hardness
gradient wherein the Shore C hardness of the outer core layer's outer
surface is at least 20 Shore C units greater, or at least 25 Shore C
units greater, or at least 30 Shore C units greater, than the inner core
layer's center Shore C hardness. In another particular embodiment, the
Shore C hardness of the outer core layer's outer surface is greater than
the material hardness of the inner cover layer.

[0014] For purposes of the present disclosure, the center hardness of the
inner core layer is obtained according to the following procedure. The
core is gently pressed into a hemispherical holder having an internal
diameter approximately slightly smaller than the diameter of the core,
such that the core is held in place in the hemispherical portion of the
holder while concurrently leaving the geometric central plane of the core
exposed. The core is secured in the holder by friction, such that it will
not move during the cutting and grinding steps, but the friction is not
so excessive that distortion of the natural shape of the core would
result. The core is secured such that the parting line of the core is
roughly parallel to the top of the holder. The diameter of the core is
measured 90 degrees to this orientation prior to securing. A measurement
is also made from the bottom of the holder to the top of the core to
provide a reference point for future calculations. A rough cut is made
slightly above the exposed geometric center of the core using a band saw
or other appropriate cutting tool, making sure that the core does not
move in the holder during this step. The remainder of the core, still in
the holder, is secured to the base plate of a surface grinding machine.
The exposed `rough` surface is ground to a smooth, flat surface,
revealing the geometric center of the core, which can be verified by
measuring the height from the bottom of the holder to the exposed surface
of the core, making sure that exactly half of the original height of the
core, as measured above, has been removed to within ±0.004 inches.
Leaving the core in the holder, the center of the core is found with a
center square and carefully marked and the hardness is measured at the
center mark according to ASTM and D-2240. Additional hardness
measurements at any distance from the center of the core can then be made
by drawing a line radially outward from the center mark, and measuring
the hardness at any given distance along the line, typically in 2 mm
increments from the center. The hardness at a particular distance from
the center should be measured along at least two, preferably four, radial
arms located 180° apart, or 90° apart, respectively, and
then averaged. All hardness measurements performed on a plane passing
through the geometric center are performed while the core is still in the
holder and without having disturbed its orientation, such that the test
surface is constantly parallel to the bottom of the holder, and thus also
parallel to the properly aligned foot of the durometer.

[0015] For purposes of the present disclosure, the outer surface hardness
of a golf ball layer is measured on the actual outer surface of the layer
and is obtained from the average of a number of measurements taken from
opposing hemispheres, taking care to avoid making measurements on the
parting line of the core or on surface defects, such as holes or
protrusions. Hardness measurements are made pursuant to ASTM D-2240
"Indentation Hardness of Rubber and Plastic by Means of a Durometer."
Because of the curved surface, care must be taken to insure that the golf
ball or golf ball subassembly is centered under the durometer indentor
before a surface hardness reading is obtained. A calibrated, digital
durometer, capable of reading to 0.1 hardness units is used for all
hardness measurements and is set to take hardness readings at 1 second
after the maximum reading is obtained. The digital durometer must be
attached to, and its foot made parallel to, the base of an automatic
stand. The weight on the durometer and attack rate conform to ASTM
D-2240.

[0016] For purposes of the present disclosure, a hardness gradient of a
golf ball layer is defined by hardness measurements made at the outer
surface of the layer and the inner surface of the layer. "Negative" and
"positive" refer to the result of subtracting the hardness value at the
innermost surface of the golf ball component from the hardness value at
the outermost surface of the component. For example, if the outer surface
of a solid core has a lower hardness value than the center (i.e., the
surface is softer than the center), the hardness gradient will be deemed
a "negative" gradient.

[0018] The inner core layer is preferably formed from a rubber
composition. Suitable rubber compositions include natural and synthetic
rubbers including, but not limited to, polybutadiene, polyisoprene,
ethylene propylene rubber ("EPR"), styrene-butadiene rubber, styrenic
block copolymer rubbers (such as SI, SIS, SB, SBS, SIBS, and the like,
where "S" is styrene, "I" is isobutylene, and "B" is butadiene), butyl
rubber, halobutyl rubber, polystyrene elastomers, polyethylene
elastomers, polyurethane elastomers, polyurea elastomers,
metallocene-catalyzed elastomers and plastomers, copolymers of
isobutylene and para-alkylstyrene, halogenated copolymers of isobutylene
and para-alkylstyrene, copolymers of butadiene with acrylonitrile,
polychloroprene, alkyl acrylate rubber, chlorinated isoprene rubber,
acrylonitrile chlorinated isoprene rubber, and combinations of two or
more thereof. Diene rubbers are preferred, particularly polybutadiene,
styrene-butadiene, and mixtures of polybutadiene with other elastomers
wherein the amount of polybutadiene present is at least 40 wt % based on
the total polymeric weight of the mixture. Suitable polybutadiene-based
and styrene-butadiene-based rubber core compositions preferably comprise
the base rubber, an initiator agent, and a coagent. Suitable examples of
commercially available polybutadienes include, but are not limited to,
Buna CB neodymium catalyzed polybutadiene rubbers, such as Buna CB 23,
and Taktene® cobalt catalyzed polybutadiene rubbers, such as
Taktene® 220 and 221, commercially available from LANXESS®
Corporation; SE BR-1220, commercially available from The Dow Chemical
Company; Europrene® NEOCIS® BR 40 and BR 60, commercially
available from Polimeri Europa®; UBEPOL-BR® rubbers, commercially
available from UBE Industries, Inc.; BR 01, commercially available from
Japan Synthetic Rubber Co., Ltd.; and Neodene neodymium catalyzed high
cis polybutadiene rubbers, such as Neodene BR 40, commercially available
from Karbochem.

[0019] Suitable initiator agents include organic peroxides, high energy
radiation sources capable of generating free radicals, and combinations
thereof. High energy radiation sources capable of generating free
radicals include, but are not limited to, electron beams, ultra-violet
radiation, gamma radiation, X-ray radiation, infrared radiation, heat,
and combinations thereof. Suitable organic peroxides include, but are not
limited to, dicumyl peroxide; n-butyl-4,4-di(t-butylperoxy) valerate;
1,1-di(t-butylperoxy)3,3,5-trimethylcyclohexane;
2,5-dimethyl-2,5-di(t-butylperoxy) hexane; di-t-butyl peroxide; di-t-amyl
peroxide; t-butyl peroxide; t-butyl cumyl peroxide;
2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3;
di(2-t-butyl-peroxyisopropyl)benzene; dilauroyl peroxide; dibenzoyl
peroxide; t-butyl hydroperoxide; lauryl peroxide; benzoyl peroxide; and
combinations thereof. In a particular embodiment, the initiator agent is
dicumyl peroxide, including, but not limited to Perkadox® BC,
commercially available from Akzo Nobel. Peroxide initiator agents are
generally present in the rubber composition in an amount of at least 0.05
parts by weight per 100 parts of the base rubber, or an amount within the
range having a lower limit of 0.05 parts or 0.1 parts or 1 part or 1.25
parts or 1.5 parts by weight per 100 parts of the base rubber, and an
upper limit of 2.5 parts or 3 parts or 5 parts or 6 parts or 10 parts or
15 parts by weight per 100 parts of the base rubber.

[0020] Coagents are commonly used with peroxides to increase the state of
cure. Suitable coagents include, but are not limited to, metal salts of
unsaturated carboxylic acids; unsaturated vinyl compounds and
polyfunctional monomers (e.g., trimethylolpropane trimethacrylate);
phenylene bismaleimide; and combinations thereof. Particular examples of
suitable metal salts include, but are not limited to, one or more metal
salts of acrylates, diacrylates, methacrylates, and dimethacrylates,
wherein the metal is selected from magnesium, calcium, zinc, aluminum,
lithium, nickel, and sodium. In a particular embodiment, the coagent is
selected from zinc salts of acrylates, diacrylates, methacrylates,
dimethacrylates, and mixtures thereof. In another particular embodiment,
the coagent is zinc diacrylate. When the coagent is zinc diacrylate
and/or zinc dimethacrylate, the coagent is typically included in the
rubber composition in an amount within the range having a lower limit of
1 or 5 or 10 or 15 or 19 or 20 parts by weight per 100 parts of the base
rubber, and an upper limit of 24 or 25 or 30 or 35 or 40 or 45 or 50 or
60 parts by weight per 100 parts of the base rubber. When one or more
less active coagents are used, such as zinc monomethacrylate and various
liquid acrylates and methacrylates, the amount of less active coagent
used may be the same as or higher than for zinc diacrylate and zinc
dimethacrylate coagents. The desired compression may be obtained by
adjusting the amount of crosslinking, which can be achieved, for example,
by altering the type and amount of coagent.

[0023] The rubber composition may also contain one or more additives
selected from processing aids, processing oils, plasticizers, coloring
agents, fluorescent agents, chemical blowing and foaming agents,
defoaming agents, stabilizers, softening agents, impact modifiers, free
radical scavengers, accelerators, scorch retarders, and the like. The
amount of additive(s) typically present in the rubber composition is
typically within a range having a lower limit of 0 parts by weight per
100 parts of the base rubber, and an upper limit of 20 parts or 50 parts
or 100 parts or 150 parts by weight per 100 parts of the base rubber.

[0024] The rubber composition optionally includes a soft and fast agent.
As used herein, "soft and fast agent" means any compound or a blend
thereof that is capable of making a core 1) softer (have a lower
compression) at a constant COR and/or 2) faster (have a higher COR) at
equal compression, when compared to a core equivalently prepared without
a soft and fast agent. Preferably, the rubber composition contains from
0.05 phr to 10.0 phr of a soft and fast agent. In one embodiment, the
soft and fast agent is present in an amount within a range having a lower
limit of 0.05 or 0.1 or 0.2 or 0.5 phr and an upper limit of 1.0 or 2.0
or 3.0 or 5.0 phr. In another embodiment, the soft and fast agent is
present in an amount of from 2.0 phr to 5.0 phr, or from 2.35 phr to 4.0
phr, or from 2.35 phr to 3.0 phr. In an alternative high concentration
embodiment, the soft and fast agent is present in an amount of from 5.0
phr to 10.0 phr, or from 6.0 phr to 9.0 phr, or from 7.0 phr to 8.0 phr.
In another embodiment, the soft and fast agent is present in an amount of
2.6 phr.

[0026] As used herein, "organosulfur compound" refers to any compound
containing carbon, hydrogen, and sulfur, where the sulfur is directly
bonded to at least 1 carbon. As used herein, the term "sulfur compound"
means a compound that is elemental sulfur, polymeric sulfur, or a
combination thereof. It should be further understood that the term
"elemental sulfur" refers to the ring structure of S8 and that
"polymeric sulfur" is a structure including at least one additional
sulfur relative to elemental sulfur.

[0027] Particularly suitable as soft and fast agents are organosulfur
compounds having the following general formula:

##STR00001##

[0028] where R1-R5 can be C1-C8 alkyl groups; halogen
groups; thiol groups (--SH), carboxylated groups; sulfonated groups; and
hydrogen; in any order; and also pentafluorothiophenol;
2-fluorothiophenol; 3-fluorothiophenol; 4-fluorothiophenol;
2,3-fluorothiophenol; 2,4-fluorothiophenol; 3,4-fluorothiophenol;
3,5-fluorothiophenol 2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol;
2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol;
4-chlorotetrafluorothiophenol; pentachlorothiophenol; 2-chlorothiophenol;
3-chlorothiophenol; 4-chlorothiophenol; 2,3-chlorothiophenol;
2,4-chlorothiophenol; 3,4-chlorothiophenol; 3,5-chlorothiophenol;
2,3,4-chlorothiophenol; 3,4,5-chlorothiophenol;
2,3,4,5-tetrachlorothiophenol; [0029] 2,3,5,6-tetrachlorothiophenol;
pentabromothiophenol; 2-bromothiophenol; 3-bromothiophenol;
4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol;
3,4-bromothiophenol; 3,5-bromothiophenol; 2,3,4-bromothiophenol;
3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiophenol;
2,3,5,6-tetrabromothiophenol; pentaiodothiophenol; 2-iodothiophenol;
3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol;
2,4-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol;
2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol;
2,3,5,6-tetraiodothiophenoland; zinc salts thereof; non-metal salts
thereof, for example, ammonium salt of pentachlorothiophenol; magnesium
pentachlorothiophenol; cobalt pentachlorothiophenol; and combinations
thereof. Preferably, the halogenated thiophenol compound is
pentachlorothiophenol, which is commercially available in neat form or
under the tradename STRUKTOL®, a clay-based carrier containing the
sulfur compound pentachlorothiophenol loaded at 45 percent (correlating
to 2.4 parts PCTP). STRUKTOL® is commercially available from Struktol
Company of America of Stow, Ohio. PCTP is commercially available in neat
form from eChinachem of San Francisco, Calif. and in the salt form from
eChinachem of San Francisco, Calif. Most preferably, the halogenated
thiophenol compound is the zinc salt of pentachlorothiophenol, which is
commercially available from eChinachem of San Francisco, Calif. Suitable
organosulfur compounds are further disclosed, for example, in U.S. Pat.
Nos. 6,635,716, 6,919,393, 7,005,479 and 7,148,279, the entire
disclosures of which are hereby incorporated herein by reference.

[0030] Suitable metal-containing organosulfur compounds include, but are
not limited to, cadmium, copper, lead, and tellurium analogs of
diethyldithiocarbamate, diamyldithiocarbamate, and
dimethyldithiocarbamate, and combinations thereof. Additional examples
are disclosed in U.S. Pat. No. 7,005,479, the entire disclosure of which
is hereby incorporated herein by reference.

[0033] Suitable Group VIA compounds include, but are not limited to,
elemental sulfur and polymeric sulfur, such as those which are
commercially available from Elastochem, Inc. of Chardon, Ohio; sulfur
catalyst compounds which include PB(RM-S)-80 elemental sulfur and
PB(CRST)-65 polymeric sulfur, each of which is available from Elastochem,
Inc; tellurium catalysts, such as TELLOY®, and selenium catalysts,
such as VANDEX®, each of which is commercially available from RT
Vanderbilt.

[0034] Suitable substituted and unsubstituted aromatic organic components
that do not include sulfur or a metal include, but are not limited to,
4,4'-diphenyl acetylene, azobenzene, and combinations thereof. The
aromatic organic group preferably ranges in size from C6 to
C20, and more preferably from C6 to C10.

[0035] Suitable substituted and unsubstituted aromatic organometallic
compounds include, but are not limited to, those having the formula
(R1)x--R3-M-R4--(R2)y, wherein R1 and
R2 are each hydrogen or a substituted or unsubstituted C1-20
linear, branched, or cyclic alkyl, alkoxy, or alkylthio group, or a
single, multiple, or fused ring C6 to C24 aromatic group; x and
y are each an integer from 0 to 5; R3 and R4 are each selected
from a single, multiple, or fused ring C6 to C24 aromatic
group; and M includes an azo group or a metal component. Preferably,
R3 and R4 are each selected from a C6 to C10 aromatic
group, more preferably selected from phenyl, benzyl, naphthyl, benzamido,
and benzothiazyl. Preferably R1 and R2 are each selected from
substituted and unsubstituted C1-10 linear, branched, and cyclic
alkyl, alkoxy, and alkylthio groups, and C6 to C10 aromatic
groups. When R1, R2, R3, and R4 are substituted, the
substitution may include one or more of the following substituent groups:
hydroxy and metal salts thereof; mercapto and metal salts thereof;
halogen; amino, nitro, cyano, and amido; carboxyl including esters,
acids, and metal salts thereof; silyl; acrylates and metal salts thereof;
sulfonyl and sulfonamide; and phosphates and phosphites. When M is a
metal component, it may be any suitable elemental metal. The metal is
generally a transition metal, and is preferably tellurium or selenium.

[0036] Suitable hydroquinones include, but are not limited to, compounds
represented by the following formula, and hydrates thereof:

##STR00002## [0037] wherein each R1, R2, R3, and
R4 is independently selected from the group consisting of hydrogen,
a halogen group (F, Cl, Br, I), an alkyl group, a carboxyl group (--COOH)
and metal salts thereof (e.g., --COO-M.sup.+) and esters thereof
(--COOR), an acetate group (--CH2COOH) and esters thereof
(--CH2COOR), a formyl group (--CHO), an acyl group (--COR), an
acetyl group (--COCH3), a halogenated carbonyl group (--COX), a
sulfo group (--SO3H) and esters thereof (--SO3R), a halogenated
sulfonyl group (--SO2X), a sulfino group (--SO2H), an
alkylsulfinyl group (--SOR), a carbamoyl group (--CONH2), a
halogenated alkyl group, a cyano group (--CN), an alkoxy group (--OR), a
hydroxy group (--OH) and metal salts thereof (e.g., --O-M.sup.+), an
amino group (--NH2), a nitro group (--NO2), an aryl group
(e.g., phenyl, tolyl, etc.), an aryloxy group (e.g., phenoxy, etc.), an
arylalkyl group [e.g., cumyl (--C(CH3)2phenyl); benzyl
(--CH2 phenyl)], a nitroso group (--NO), an acetamido group
(--NHCOCH3), and a vinyl group (--CH═CH2). Particularly
preferred hydroquinones include compounds represented by the above
formula, and hydrates thereof, wherein each R1, R2, R3,
and R4 is independently selected from the group consisting of: a
metal salt of a carboxyl group (e.g., --COO-M.sup.+), an acetate
group (--CH2COOH) and esters thereof (--CH2COOR), a hydroxy
group (--OH), a metal salt of a hydroxy group (e.g., --O-M.sup.+),
an amino group (--NH2), a nitro group (--NO2), an aryl group
(e.g., phenyl, tolyl, etc.), an aryloxy group (e.g., phenoxy, etc.), an
arylalkyl group [e.g., cumyl (--C(CH3)2phenyl); benzyl
(--CH2 phenyl)], a nitroso group (--NO), an acetamido group
(--NHCOCH3), and a vinyl group (--CH═CH2). Examples of
particularly suitable hydroquinones include, but are not limited to,
hydroquionone; tetrachlorohydroquinone; 2-chlorohydroquionone;
2-bromohydroquinone; 2,5-dichlorohydroquinone; 2,5-dibromohydroquinone;
tetrabromohydroquinone; 2-methylhydroquinone; 2-t-butylhydroquinone;
2,5-di-t-amylhydroquinone; and 2-(2-chlorophenyl)hydroquinone hydrate.
Hydroquinone and tetrachlorohydroquinone are particularly preferred, and
even more particularly preferred is 2-(2-chlorophenyl)hydroquinone
hydrate. Suitable hydroquinones are further disclosed, for example, in
U.S. Patent Application Publication No. 2007/0213440, the entire
disclosure of which is hereby incorporated herein by reference.

[0038] Suitable benzoquinones include compounds represented by the
following formula, and hydrates thereof:

##STR00003## [0039] wherein each R1, R2, R3, and
R4 is independently selected from the group consisting of hydrogen,
a halogen group (F, Cl, Br, I), an alkyl group, a carboxyl group (--COOH)
and metal salts thereof (e.g., --COO-M.sup.+) and esters thereof
(--COOR), an acetate group (--CH2COOH) and esters thereof
(--CH2COOR), a formyl group (--CHO), an acyl group (--COR), an
acetyl group (--COCH3), a halogenated carbonyl group (--COX), a
sulfo group (--SO3H) and esters thereof (--SO3R), a halogenated
sulfonyl group (--SO2X), a sulfino group (--SO2H), an
alkylsulfinyl group (--SOR), a carbamoyl group (--CONH2), a
halogenated alkyl group, a cyano group (--CN), an alkoxy group (--OR), a
hydroxy group (--OH) and metal salts thereof (e.g., --O-M.sup.+), an
amino group (--NH2), a nitro group (--NO2), an aryl group
(e.g., phenyl, tolyl, etc.), an aryloxy group (e.g., phenoxy, etc.), an
arylalkyl group [e.g., cumyl (--C(CH3)2phenyl); benzyl
(--CH2 phenyl)], a nitroso group (--NO), an acetamido group
(--NHCOCH3), and a vinyl group (--CH═CH2). Particularly
preferred benzoquinones include compounds represented by the above
formula, and hydrates thereof, wherein each R1, R2, R3,
and R4 is independently selected from the group consisting of: a
metal salt of a carboxyl group (e.g., --COO-M.sup.+), an acetate
group (--CH2COOH) and esters thereof (--CH2COOR), a hydroxy
group (--OH), a metal salt of a hydroxy group (e.g., -O-M.sup.+), an
amino group (--NH2), a nitro group (--NO2), an aryl group
(e.g., phenyl, tolyl, etc.), an aryloxy group (e.g., phenoxy, etc.), an
arylalkyl group [e.g., cumyl (--C(CH3)2phenyl); benzyl
(--CH2 phenyl)], a nitroso group (--NO), an acetamido group
(--NHCOCH3), and a vinyl group (--CH═CH2). Methyl
p-benzoquinone and tetrachloro p-benzoquinone are more particularly
preferred. Suitable benzoquinones are further disclosed, for example, in
U.S. Patent Application Publication No. 2007/0213442, the entire
disclosure of which is hereby incorporated herein by reference.

[0040] Suitable quinhydrones include, but are not limited to, compounds
represented by the following formula, and hydrates thereof:

##STR00004## [0041] wherein each R1, R2, R3, R4,
R5, R6, R7, and R8 is independently selected from the
group consisting of hydrogen, a halogen group (F, Cl, Br, I), an alkyl
group, a carboxyl group (--COOH) and metal salts thereof (e.g.,
--COO-M.sup.+) and esters thereof (--COOR), an acetate group
(--CH2COOH) and esters thereof (--CH2COOR), a formyl group
(--CHO), an acyl group (--COR), an acetyl group (--COCH3), a
halogenated carbonyl group (--COX), a sulfo group (--SO3H) and
esters thereof (--SO3R), a halogenated sulfonyl group (--SO2X),
a sulfino group (--SO2H), an alkylsulfinyl group (--SOR), a
carbamoyl group (--CONH2), a halogenated alkyl group, a cyano group
(--CN), an alkoxy group (--OR), a hydroxy group (--OH) and metal salts
thereof (e.g., --O-M.sup.+), an amino group (--NH2), a nitro
group (--NO2), an aryl group (e.g., phenyl, tolyl, etc.), an aryloxy
group (e.g., phenoxy, etc.), an arylalkyl group [e.g., cumyl
(--C(CH3)2phenyl); benzyl (--CH2 phenyl)], a nitroso group
(--NO), an acetamido group (--NHCOCH3), and a vinyl group
(--CH═CH2). Particularly preferred quinhydrones include
compounds represented by the above formula, and hydrates thereof, wherein
each R1, R2, R3, R4, R5, R6, R7, and
R8 is independently selected from the group consisting of: a metal
salt of a carboxyl group (e.g., --COO-M.sup.+), an acetate group
(--CH2COOH) and esters thereof (--CH2COOR), a hydroxy group
(--OH), a metal salt of a hydroxy group (e.g., --O-M.sup.+), an
amino group (--NH2), a nitro group (--NO2), an aryl group
(e.g., phenyl, tolyl, etc.), an aryloxy group (e.g., phenoxy, etc.), an
arylalkyl group [e.g., cumyl (--C(CH3)2phenyl); benzyl
(--CH2 phenyl)], a nitroso group (--NO), an acetamido group
(--NHCOCH3), and a vinyl group (--CH═CH2). Particularly
preferred quinhydrones also include compounds represented by the above
formula wherein each R1, R2, R3, R4, R5,
R6, R7, and R8 is hydrogen. Suitable quinhydrones are
further disclosed, for example, in U.S. Patent Application Publication
No. 2007/0213441, the entire disclosure of which is hereby incorporated
herein by reference.

[0042] Suitable catechols include compounds represented by the following
formula, and hydrates thereof:

##STR00005## [0043] wherein each R1, R2, R3, and
R4, is independently selected from the group consisting of hydrogen,
a halogen group (F, Cl, Br, I), an alkyl group, a carboxyl group (--COOH)
and metal salts thereof (e.g., --COO-M.sup.+) and esters thereof
(--COOR), an acetate group (--CH2COOH) and esters thereof
(--CH2COOR), a formyl group (--CHO), an acyl group (--COR), an
acetyl group (--COCH3), a halogenated carbonyl group (--COX), a
sulfo group (--SO3H) and esters thereof (--SO3R), a halogenated
sulfonyl group (--SO2X), a sulfino group (--SO2H), an
alkylsulfinyl group (--SOR), a carbamoyl group (--CONH2), a
halogenated alkyl group, a cyano group (--CN), an alkoxy group (--OR), a
hydroxy group (--OH) and metal salts thereof (e.g., --O-M.sup.+), an
amino group (--NH2), a nitro group (--NO2), an aryl group
(e.g., phenyl, tolyl, etc.), an aryloxy group (e.g., phenoxy, etc.), an
arylalkyl group [e.g., cumyl (--C(CH3)2phenyl); benzyl
(--CH2 phenyl)], a nitroso group (--NO), an acetamido group
(--NHCOCH3), and a vinyl group (--CH═CH2). Suitable
catechols are further disclosed, for example, in U.S. Patent Application
Publication No. 2007/0213144, the entire disclosure of which is hereby
incorporated herein by reference.

[0044] Suitable resorcinols include compounds represented by the following
formula, and hydrates thereof:

##STR00006## [0045] wherein each R1, R2, R3, and
R4, is independently selected from the group consisting of hydrogen,
a halogen group (F, Cl, Br, I), an alkyl group, a carboxyl group (--COOH)
and metal salts thereof (e.g., --COO-M.sup.+) and esters thereof
(--COOR), an acetate group (--CH2COOH) and esters thereof
(--CH2COOR), a formyl group (--CHO), an acyl group (--COR), an
acetyl group (--COCH3), a halogenated carbonyl group (--COX), a
sulfo group (--SO3H) and esters thereof (--SO3R), a halogenated
sulfonyl group (--SO2X), a sulfino group (--SO2H), an
alkylsulfinyl group (--SOR), a carbamoyl group (--CONH2), a
halogenated alkyl group, a cyano group (--CN), an alkoxy group (--OR), a
hydroxy group (--OH) and metal salts thereof (e.g., --O-M.sup.+), an
amino group (--NH2), a nitro group (--NO2), an aryl group
(e.g., phenyl, tolyl, etc.), an aryloxy group (e.g., phenoxy, etc.), an
arylalkyl group [e.g., cumyl (--C(CH3)2phenyl); benzyl
(--CH2 phenyl)], a nitroso group (--NO), an acetamido group
(--NHCOCH3), and a vinyl group (--CH═CH2).
2-Nitroresorcinol is particularly preferred. Suitable resorcinols are
further disclosed, for example, in U.S. Patent Application Publication
No. 2007/0213144, the entire disclosure of which is hereby incorporated
herein by reference.

[0046] When the rubber composition includes one or more hydroquinones,
benzoquinones, quinhydrones, catechols, resorcinols, or a combination
thereof, the total amount of hydroquinone(s), benzoquinone(s),
quinhydrone(s), catechol(s), and/or resorcinol(s) present in the
composition is typically at least 0.1 parts by weight or at least 0.15
parts by weight or at least 0.2 parts by weight per 100 parts of the base
rubber, or an amount within the range having a lower limit of 0.1 parts
or 0.15 parts or 0.25 parts or 0.3 parts or 0.375 parts by weight per 100
parts of the base rubber, and an upper limit of 0.5 parts or 1 part or
1.5 parts or 2 parts or 3 parts by weight per 100 parts of the base
rubber.

[0048] Suitable types and amounts of base rubber, initiator agent,
coagent, filler, and additives are more fully described in, for example,
U.S. Pat. Nos. 6,566,483, 6,695,718, and 6,939,907, 7,041,721 and
7,138,460, the entire disclosures of which are hereby incorporated herein
by reference.

[0049] The outer core layer is preferably formed from a highly resilient
thermoplastic polymer such as a highly neutralized polymer ("HNP")
composition. HNP compositions suitable for use in forming the outer core
layer of golf balls of the present invention preferably have a material
hardness of 35 Shore D or greater, and more preferably have a hardness of
45 Shore D or greater or a hardness within a range having a lower limit
of 45 or 50 or 55 or 57 or 58 or 60 or 65 or 70 or 75 Shore D and an
upper limit of 80 or 85 or 90 or 95 Shore D.

[0050] Suitable HNP compositions for use in forming the outer core layer
comprise an HNP and optionally melt flow modifier(s), additive(s), and/or
filler(s). Suitable HNPs are salts of acid copolymers. It is understood
that the HNP may be a blend of two or more HNPs. Preferred acid
copolymers are copolymers of an α-olefin and a C3-C8
α,β-ethylenically unsaturated carboxylic acid. The acid is
typically present in the acid copolymer in an amount within a range
having a lower limit of 1 or 10 or 12 or 15 or 20 wt % and an upper limit
of 25 or 30 or 35 or 40 wt %, based on the total weight of the acid
copolymer. The α-olefin is preferably selected from ethylene and
propylene. The acid is preferably selected from (meth) acrylic acid,
ethacrylic acid, maleic acid, crotonic acid, fumaric acid, and itaconic
acid. (Meth) acrylic acid is particularly preferred. Suitable acid
copolymers include partially neutralized acid polymers. Examples of
suitable partially neutralized acid polymers include, but are not limited
to, Surlyn® ionomers, commercially available from E.I. du Pont de
Nemours and Company; AClyn® ionomers, commercially available from
Honeywell International Inc.; and Iotek® ionomers, commercially
available from ExxonMobil Chemical Company. Also suitable are DuPont®
HPF 1000 and DuPont® HPF 2000, ionomeric materials commercially
available from E.I. du Pont de Nemours and Company. In a preferred
embodiment, the acid polymer of the HNP outer core layer composition has
a modulus within a range having a lower limit of 25,000 or 27,000 or
30,000 or 40,000 or 45,000 or 50,000 or 55,000 or 60,000 psi and an upper
limit of 72,000 or 75,000 or 100,000 or 150,000 psi. As used herein,
"modulus" refers to flexural modulus as measured using a standard flex
bar according to ASTM D790-B. Additional suitable acid polymers are more
fully described, for example, in U.S. Pat. Nos. 6,562,906, 6,762,246, and
6,953,820 and U.S. Patent Application Publication Nos. 2005/0049367,
2005/0020741, and 2004/0220343, the entire disclosures of which are
hereby incorporated herein by reference.

[0051] The HNP is formed by reacting the acid copolymer with a sufficient
amount of cation source such that at least 80%, preferably at least 90%,
more preferably at least 95%, and even more preferably 100%, of all acid
groups present are neutralized. Suitable cation sources include metal
ions and compounds of alkali metals, alkaline earth metals, and
transition metals; metal ions and compounds of rare earth elements;
silicone, silane, and silicate derivatives and complex ligands; and
combinations thereof. Preferred cation sources are metal ions and
compounds of magnesium, sodium, potassium, cesium, calcium, barium,
manganese, copper, zinc, tin, lithium, and rare earth metals. Metal ions
and compounds of calcium and magnesium are particularly preferred. The
acid copolymer may be at least partially neutralized prior to contacting
the acid copolymer with the cation source to form the HNP. Methods of
preparing ionomers, and the acid copolymers on which ionomers are based,
are disclosed, for example, in U.S. Pat. Nos. 3,264,272, and 4,351,931,
and U.S. Patent Application Publication No. 2002/0013413.

[0052] HNP outer core layer compositions of the present invention
optionally contain one or more melt flow modifiers. The amount of melt
flow modifier in the composition is readily determined such that the melt
flow index of the composition is at least 0.1 g/10 min, preferably from
0.5 g/10 min to 10.0 g/10 min, and more preferably from 1.0 g/10 min to
6.0 g/10 min, as measured using ASTM D-1238, condition E, at 190°
C., using a 2160 gram weight.

[0054] Additional melt flow modifiers suitable for use in compositions of
the present invention, include the non-fatty acid melt flow modifiers
described in U.S. Pat. Nos. 7,365,128 and 7,402,629, the entire
disclosures of which are hereby incorporated herein by reference.

[0056] In a particular embodiment, the HNP outer core layer composition
has a moisture vapor transmission rate ("MVTR") of 8 g-mil/100
in2/day or less (i.e., 3.2 g-mm/m2-day or less), or 5 g-mil/100
in2/day or less (i.e., 2.0 g-mm/m2-day or less), or 3 g-mil/100
in2/day or less (i.e., 1.2 g-mm/m2-day or less), or 2 g-mil/100
in2/day or less (i.e., 0.8 g-mm/m2-day or less), or 1 g-mil/100
in2/day or less (i.e., 0.4 g-mm/m2-day or less), or less than 1
g-mil/100 in2/day (i.e., less than 0.4 g-mm/m2-day). Suitable
moisture resistant HNP compositions are disclosed, for example, in U.S.
Patent Application Publication Nos. 2005/0267240, 2006/0106175 and
2006/0293464, the entire disclosures of which are hereby incorporated
herein by reference.

[0057] In another particular embodiment, a sphere formed from the HNP
outer core layer composition has a compression of 70 or greater, or 80 or
greater, or a compression within a range having a lower limit of 70 or 80
or 90 or 100 and an upper limit of 110 or 130 or 140.

[0058] HNP outer core layer compositions of the present invention are not
limited by any particular method or any particular equipment for making
the compositions. In a preferred embodiment, the composition is prepared
by the following process. The acid polymer(s), preferably an
ethylene/(meth) acrylic acid copolymer, optional melt flow modifier(s),
and optional additive(s)/filler(s) are simultaneously or individually fed
into a melt extruder, such as a single or twin screw extruder. A suitable
amount of cation source is then added such that at least 80%, preferably
at least 90%, more preferably at least 95%, and even more preferably
100%, of all acid groups present are neutralized. The acid polymer may be
at least partially neutralized prior to the above process. The components
are intensively mixed prior to being extruded as a strand from the
die-head.

[0059] Suitable HNP outer core layer compositions of the present invention
also include blends of HNPs with partially neutralized ionomers as
disclosed, for example, in U.S. Patent Application Publication No.
2006/0128904, the entire disclosure of which is hereby incorporated
herein by reference, and blends of HNPs with additional thermoplastic and
elastomeric materials. Examples of thermoplastic materials suitable for
blending include bimodal ionomers (e.g., as disclosed in U.S. Patent
Application Publication No. 2004/0220343 and U.S. Pat. Nos. 6,562,906,
6,762,246 and 7,273,903, the entire disclosures of which are hereby
incorporated herein by reference), ionomers modified with rosins (e.g.,
as disclosed in U.S. Patent Application Publication No. 2005/0020741, the
entire disclosure of which is hereby incorporated by reference), soft and
resilient ethylene copolymers (e.g., as disclosed U.S. Patent Application
Publication No. 2003/0114565, the entire disclosure of which is hereby
incorporated herein by reference), polyolefins, polyamides, polyesters,
polyethers, polycarbonates, polysulfones, polyacetals, polylactones,
acrylonitrile-butadiene-styrene resins, polyphenylene oxide,
polyphenylene sulfide, styrene-acrylonitrile resins, styrene maleic
anhydride, polyimides, aromatic polyketones, ionomers and ionomeric
precursors, acid copolymers, conventional HNPs, polyurethanes, grafted
and non-grafted metallocene-catalyzed polymers, single-site catalyst
polymerized polymers, high crystalline acid polymers, cationic ionomers,
and combinations thereof. Particular polyolefins suitable for blending
include one or more, linear, branched, or cyclic, C2-C40
olefins, particularly polymers comprising ethylene or propylene
copolymerized with one or more C2-C40 olefins, C3-C20
α-olefins, or C3-C10 α-olefins. Particular
conventional HNPs suitable for blending include, but are not limited to,
one or more of the HNPs disclosed in U.S. Pat. Nos. 6,756,436, 6,894,098,
and 6,953,820, the entire disclosures of which are hereby incorporated
herein by reference. Examples of elastomers suitable for blending include
natural and synthetic rubbers, including, but not limited to, ethylene
propylene rubber ("EPR"), ethylene propylene diene rubber ("EPDM"),
styrenic block copolymer rubbers (such as SI, SIS, SB, SBS, SIBS, and the
like, where "S" is styrene, "I" is isobutylene, and "B" is butadiene),
butyl rubber, halobutyl rubber, copolymers of isobutylene and
para-alkylstyrene, halogenated copolymers of isobutylene and
para-alkylstyrene, natural rubber, polyisoprene, copolymers of butadiene
with acrylonitrile, polychloroprene, alkyl acrylate rubber, chlorinated
isoprene rubber, acrylonitrile chlorinated isoprene rubber, and
polybutadiene rubber (cis and trans). Additional suitable blend polymers
include those described in U.S. Pat. No. 5,981,658, for example at column
14, lines 30 to 56, the entire disclosure of which is hereby incorporated
herein by reference. The blends described herein may be produced by
post-reactor blending, by connecting reactors in series to make reactor
blends, or by using more than one catalyst in the same reactor to produce
multiple species of polymer. The polymers may be mixed prior to being put
into an extruder, or they may be mixed in an extruder.

[0060] HNP outer core layer compositions of the present invention, in the
neat (i.e., unfilled) form, preferably have a specific gravity of from
0.95 g/cc to 0.99 g/cc. Any suitable filler, flake, fiber, particle, or
the like, of an organic or inorganic material may be added to the HNP
composition to increase or decrease the specific gravity, particularly to
adjust the weight distribution within the golf ball, as further disclosed
in U.S. Pat. Nos. 6,494,795, 6,547,677, 6,743,123, 7,074,137, and
6,688,991, the entire disclosures of which are hereby incorporated herein
by reference.

[0061] Suitable HNP compositions are further disclosed, for example, in
U.S. Pat. Nos. 6,653,382, 6,756,436, 6,777,472, 6,894,098, 6,919,393, and
6,953,820, the entire disclosures of which are hereby incorporated herein
by reference.

[0062] Particularly suitable for use in forming outer core layers of golf
balls of the present invention are the "relatively hard HNP compositions"
disclosed in U.S. Patent Application Publication No. 2007/0207879, the
"high modulus HNP compositions" disclosed in U.S. Pat. No. 7,207,903, and
the highly neutralized acid polymer compositions disclosed in U.S. Pat.
No. 6,994,638, the entire disclosures of which are hereby incorporated
herein by reference.

[0063] The outer core layer is alternatively formed from a highly
resilient thermoplastic polymer composition selected from Hytrel®
thermoplastic polyester elastomers, commercially available from E.I. du
Pont de Nemours and Company, and Pebax® thermoplastic polyether block
amides, commercially available from Arkema Inc.

[0064] Additional materials suitable for forming the inner and outer core
layers include the core compositions disclosed in U.S. Pat. No.
7,300,364, the entire disclosure of which is hereby incorporated herein
by reference. For example, suitable core materials include HNPs
neutralized with organic fatty acids and salts thereof, metal cations, or
a combination of both. In addition to HNPs neutralized with organic fatty
acids and salts thereof, core compositions may comprise at least one
rubber material having a resilience index of at least about 40.
Preferably the resilience index is at least about 50.

[0065] The weight distribution of the cores disclosed herein can be varied
to achieve certain desired parameters, such as spin rate, compression,
and initial velocity.

[0066] The two-layer core is enclosed with a cover comprising an inner
cover layer and an outer cover layer. According to the present invention,
the surface hardness of the outer core layer's outer surface is greater
than the material hardness of the inner cover layer. In a particular
embodiment, the surface hardness of the outer core layer's outer surface
is greater than the material hardness of both the inner cover layer and
the outer cover layer.

[0067] It should be understood that there is a fundamental difference
between "material hardness" and "hardness as measured directly on a golf
ball." For purposes of the present disclosure, material hardness is
measured according to ASTM D2240 and generally involves measuring the
hardness of a flat "slab" or "button" formed of the material. Hardness as
measured directly on a golf ball (or other spherical surface) typically
results in a different hardness value. This difference in hardness values
is due to several factors including, but not limited to, ball
construction (i.e., core type, number of core and/or cover layers, etc.),
ball (or sphere) diameter, and the material composition of adjacent
layers. It should also be understood that the two measurement techniques
are not linearly related and, therefore, one hardness value cannot easily
be correlated to the other. Unless otherwise stated, the material
hardness values given herein for cover materials are measured according
to ASTM D2240, with all values reported following 10 days of aging at 50%
relative humidity and 23° C.

[0068] The inner cover layer preferably has an outer surface hardness of
95 Shore C or less, or an outer surface hardness within a range having a
lower limit of 80 or 85 or 87 Shore C and an upper limit of 90 or 91 or
95 Shore C. For purposes of the present disclosure, the outer surface
hardness of the inner cover layer is measured according to the procedure
given herein for measuring the outer surface hardness of a golf ball
layer.

[0069] The inner cover layer preferably has a material hardness
(Hinner cover) of 95 Shore C or less, or less than 95 Shore C, or 92
Shore C or less, or 90 Shore C or less, or has a material hardness
(Hinner cover) within a range having a lower limit of 70 or 75 or 80
or 84 or 85 or 87 Shore C and an upper limit of 90 or 91 or 92 or 95
Shore C. The thickness of the inner cover layer is preferably within a
range having a lower limit of 0.010 or 0.015 or 0.020 or 0.025 or 0.030
inches and an upper limit of 0.035 or 0.045 or 0.050 or 0.080 or 0.120 or
0.150 inches.

[0070] The outer cover layer preferably has an outer surface hardness
within a range having a lower limit of 20 or 30 or 35 or 40 Shore D and
an upper limit of 52 or 58 or 60 or 65 or 70 or 72 or 75 Shore D.

[0071] The outer cover layer preferably has a material hardness of 85
Shore C or less. The thickness of the outer cover layer is preferably
within a range having a lower limit of 0.010 or 0.015 or 0.020 or 0.025
inches and an upper limit of 0.035 or 0.040 or 0.050 or 0.055 or 0.080
inches.

[0072] Optional intermediate cover layers may be included and generally
have a thickness within a range having a lower limit of 0.010 or 0.020 or
0.025 inches and an upper limit of 0.050 or 0.150 or 0.200 inches.

[0073] The cover preferably has an overall thickness within a range having
a lower limit of 0.010 or 0.020 or 0.025 or 0.030 or 0.040 or 0.045 or
0.050 or 0.060 inches and an upper limit of 0.070 or 0.075 or 0.080 or
0.090 or 0.100 or 0.150 or 0.200 or 0.300 or 0.500 inches.

[0075] Compositions comprising an ionomer or a blend of two or more
ionomers are particularly suitable for forming the inner cover layer in
dual-layer covers. Preferred ionomeric compositions include: [0076] (a)
a composition comprising a "high acid ionomer" (i.e., having an acid
content of greater than 16 wt %), such as Surlyn 8150®, a copolymer
of ethylene and methacrylic acid, having an acid content of 19 wt %,
which is 45% neutralized with sodium; [0077] (b) a composition comprising
a high acid ionomer and a maleic anhydride-grafted non-ionomeric polymer
(e.g., Fusabond® maleic anhydride-grafted metallocene-catalyzed
ethylene-butene copolymers). A particularly preferred blend of high acid
ionomer and maleic anhydride-grafted polymer is a blend of 79-85 wt %
Surlyn 8150® and 15-21 wt % Fusabond®. Blends of high acid
ionomers with maleic anhydride-grafted polymers are further disclosed,
for example, in U.S. Pat. Nos. 6,992,135 and 6,677,401, the entire
disclosures of which are hereby incorporated herein by reference; [0078]
(c) a composition comprising a 50/45/5 blend of Surlyn®
8940/Surlyn® 9650/Nucrel® 960, preferably having a material
hardness of from 80 to 85 Shore C; [0079] (d) a composition comprising a
50/25/25 blend of Surlyn® 8940/Surlyn® 9650/Surlyn® 9910,
preferably having a material hardness of about 90 Shore C; [0080] (e) a
composition comprising a 50/50 blend of Surlyn® 8940/Surlyn®
9650, preferably having a material hardness of about 86 Shore C; [0081]
(f) a composition comprising a blend of Surlyn® 7940/Surlyn®
8940, optionally including a melt flow modifier; [0082] (g) a composition
comprising a blend of a first high acid ionomer and a second high acid
ionomer, wherein the first high acid ionomer is neutralized with a
different cation than the second high acid ionomer (e.g., 50/50 blend of
Surlyn® 8150 and Surlyn® 9150), optionally including one or more
melt flow modifiers such as an ionomer, ethylene-acid copolymer or ester
terpolymer; and [0083] (h) a composition comprising a blend of a first
high acid ionomer and a second high acid ionomer, wherein the first high
acid ionomer is neutralized with a different cation than the second high
acid ionomer, and from 0 to 10 wt % of an ethylene/acid/ester ionomer
wherein the ethylene/acid/ester ionomer is neutralized with the same
cation as either the first high acid ionomer or the second high acid
ionomer or a different cation than the first and second high acid
ionomers (e.g., a blend of 40-50 wt % Surlyn® 8140, 40-50 wt %
Surlyn® 9120, and 0-10 wt % Surlyn® 6320).

[0084] Surlyn 8150®, Surlyn® 8940, and Surlyn® 8140 are
different grades of E/MAA copolymer in which the acid groups have been
partially neutralized with sodium ions. Surlyn® 9650, Surlyn®
9910, Surlyn® 9150, and Surlyn® 9120 are different grades of
E/MAA copolymer in which the acid groups have been partially neutralized
with zinc ions. Surlyn® 7940 is an E/MAA copolymer in which the acid
groups have been partially neutralized with lithium ions. Surlyn®
6320 is a very low modulus magnesium ionomer with a medium acid content.
Nucrel® 960 is an E/MAA copolymer resin nominally made with 15 wt %
methacrylic acid. Surlyn® ionomers, Fusabond® copolymers, and
Nucrel® copolymers are commercially available from E.I. du Pont de
Nemours and Company.

[0087] Suitable ionomeric cover materials are further disclosed, for
example, in U.S. Pat. Nos. 6,653,382, 6,756,436, 6,894,098, 6,919,393,
and 6,953,820, the entire disclosures of which are hereby incorporated by
reference.

[0088] Polyurethanes, polyureas, and copolymers and blends thereof are
particularly suitable for forming the outer cover layer in dual-layer
covers. When used as cover layer materials, polyurethanes and polyureas
can be thermoset or thermoplastic. Thermoset materials can be formed into
golf ball layers by conventional casting or reaction injection molding
techniques. Thermoplastic materials can be formed into golf ball layers
by conventional compression or injection molding techniques.

[0089] Suitable polyurethane cover materials are further disclosed in U.S.
Pat. Nos. 5,334,673, 6,506,851, 6,756,436, and 7,105,623, the entire
disclosures of which are hereby incorporated herein by reference.
Suitable polyurea cover materials are further disclosed in U.S. Pat. Nos.
5,484,870, 6,835,794 and 7,378,483, and U.S. Patent Application
Publication No. 2008/0064527, the entire disclosures of which are hereby
incorporated herein by reference. Suitable polyurethane-urea cover
materials include polyurethane/polyurea blends and copolymers comprising
urethane and urea segments, as disclosed in U.S. Patent Application
Publication No. 2007/0117923, the entire disclosure of which is hereby
incorporated herein by reference.

[0090] Golf ball cover compositions may include a flow modifier, such as,
but not limited to, Nucrel® acid copolymer resins, and particularly
Nucrel® 960. Nucrel® acid copolymer resins are commercially
available from E.I. du Pont de Nemours and Company.

[0092] In a particular embodiment, the cover comprises an inner cover
layer formed from a composition comprising a high acid ionomer and a
maleic anhydride-grafted non-ionomeric polymer and an outer cover layer
formed from a polyurethane, polyurea, or copolymer or hybrid of
polyurethane/polyurea. The outer cover layer material may be
thermoplastic or thermoset. A particularly preferred inner cover layer
composition is a 84 wt %/16 wt % blend of Surlyn 8150® and Fusabond
572D®.

[0093] Additional suitable cover materials are disclosed, for example, in
U.S. Patent Application Publication No. 2005/0164810, U.S. Pat. No.
5,919,100, and PCT Publications WO00/23519 and WO00/29129, the entire
disclosures of which are hereby incorporated herein by reference.

[0095] A moisture vapor barrier layer is optionally employed between the
core and the cover. Moisture vapor barrier layers are further disclosed,
for example, in U.S. Pat. Nos. 6,632,147, 6,932,720, 7,004,854, and
7,182,702, the entire disclosures of which are hereby incorporated herein
by reference.

[0097] Other preferred materials suitable for use as an additional
material in golf ball compositions disclosed herein include Skypel
polyester elastomers, commercially available from SK Chemicals of South
Korea; Septon® diblock and triblock copolymers, commercially
available from Kuraray Corporation of Kurashiki, Japan; and Kraton®
diblock and triblock copolymers, commercially available from Kraton
Polymers LLC of Houston, Tex.

[0099] The present invention is not limited by any particular process for
forming the golf ball layer(s). It should be understood that the layer(s)
can be formed by any suitable technique, including injection molding,
compression molding, casting, and reaction injection molding.

[0100] When injection molding is used, the composition is typically in a
pelletized or granulated form that can be easily fed into the throat of
an injection molding machine wherein it is melted and conveyed via a
screw in a heated barrel at temperatures of from 150° F. to
600° F., preferably from 200° F. to 500° F. The
molten composition is ultimately injected into a closed mold cavity,
which may be cooled, at ambient or at an elevated temperature, but
typically the mold is cooled to a temperature of from 50° F. to
70° F. After residing in the closed mold for a time of from 1
second to 300 seconds, preferably from 20 seconds to 120 seconds, the
core and/or core plus one or more additional core or cover layers is
removed from the mold and either allowed to cool at ambient or reduced
temperatures or is placed in a cooling fluid such as water, ice water,
dry ice in a solvent, or the like.

[0101] When compression molding is used to form a core, the composition is
first formed into a preform or slug of material, typically in a
cylindrical or roughly spherical shape at a weight slightly greater than
the desired weight of the molded core. Prior to this step, the
composition may be first extruded or otherwise melted and forced through
a die after which it is cut into a cylindrical preform. The preform is
then placed into a compression mold cavity and compressed at a mold
temperature of from 150° F. to 400° F., preferably from
250° F. to 400° F., and more preferably from 300° F.
to 400° F. When compression molding a cover layer, half-shells of
the cover layer material are first formed via injection molding. A core
is then enclosed within two half-shells, which is then placed into a
compression mold cavity and compressed.

[0102] Reaction injection molding processes are further disclosed, for
example, in U.S. Pat. Nos. 6,083,119, 7,208,562, 7,281,997, 7,282,169,
7,338,391, and U.S. Patent Application Publication No. 2006/0247073, the
entire disclosures of which are hereby incorporated herein by reference.

[0103] Golf balls of the present invention typically have a coefficient of
restitution ("COR") of 0.700 or greater, preferably 0.750 or greater,
more preferably 0.780 or greater, and even more preferably 0.790 or
greater.

[0104] COR, as used herein, is determined according to a known procedure
wherein a golf ball or golf ball subassembly (e.g., a golf ball core) is
fired from an air cannon at two given velocities and calculated at a
velocity of 125 ft/s. Ballistic light screens are located between the air
cannon and the steel plate at a fixed distance to measure ball velocity.
As the ball travels toward the steel plate, it activates each light
screen, and the time at each light screen is measured. This provides an
incoming transit time period inversely proportional to the ball's
incoming velocity. The ball impacts the steel plate and rebounds though
the light screens, which again measure the time period required to
transit between the light screens. This provides an outgoing transit time
period inversely proportional to the ball's outgoing velocity. COR is
then calculated as the ratio of the outgoing transit time period to the
incoming transit time period, COR=Vout/Vin=Tin/Tout.

[0105] Golf balls of the present invention typically have an overall
compression of 40 or greater, or a compression within a range having a
lower limit of 40 or 50 or 60 or 65 or 75 or 80 or 90 and an upper limit
of 95 or 100 or 105 or 110 or 115 or 120. Dual cores of the present
invention preferably have an overall compression of 60 or 70 or 75 or 80
and an upper limit of 85 or 90 or 95 or 100. Inner core layers of the
present invention preferably have a compression of 40 or less, or from 20
to 40, or a compression of about 30.

[0106] Compression is an important factor in golf ball design. For
example, the compression of the core can affect the ball's spin rate off
the driver and the feel. As disclosed in Jeff Dalton's Compression by Any
Other Name, Science and Golf IV, Proceedings of the World Scientific
Congress of Golf (Eric Thain ed., Routledge, 2002) ("J. Dalton"), several
different methods can be used to measure compression, including Atti
compression, Riehle compression, load/deflection measurements at a
variety of fixed loads and offsets, and effective modulus. For purposes
of the present invention, "compression" refers to Atti compression and is
measured according to a known procedure, using an Atti compression test
device, wherein a piston is used to compress a ball against a spring. The
travel of the piston is fixed and the deflection of the spring is
measured. The measurement of the deflection of the spring does not begin
with its contact with the ball; rather, there is an offset of
approximately the first 1.25 mm (0.05 inches) of the spring's deflection.
Very low stiffness cores will not cause the spring to deflect by more
than 1.25 mm and therefore have a zero compression measurement. The Atti
compression tester is designed to measure objects having a diameter of
42.7 mm (1.68 inches); thus, smaller objects, such as golf ball cores,
must be shimmed to a total height of 42.7 mm to obtain an accurate
reading. Conversion from Atti compression to Riehle (cores), Riehle
(balls), 100 kg deflection, 130-10 kg deflection or effective modulus can
be carried out according to the formulas given in J. Dalton.

[0107] Golf balls of the present invention will typically have dimple
coverage of 60% or greater, preferably 65% or greater, and more
preferably 75% or greater.

[0108] The United States Golf Association specifications limit the minimum
size of a competition golf ball to 1.680 inches. There is no
specification as to the maximum diameter, and golf balls of any size can
be used for recreational play. Golf balls of the present invention can
have an overall diameter of any size. The preferred diameter of the
present golf balls is from 1.680 inches to 1.800 inches. More preferably,
the present golf balls have an overall diameter of from 1.680 inches to
1.760 inches, and even more preferably from 1.680 inches to 1.740 inches.

[0109] Golf balls of the present invention preferably have a moment of
inertia ("MOI") of 70-95 g-cm2, preferably 75-93 g-cm2, and
more preferably 76-90 g-cm2. For low MOI embodiments, the golf ball
preferably has an MOI of 85 g-cm2 or less, or 83 g-cm2 or less.
For high MOI embodiment, the golf ball preferably has an MOI of 86
g-cm2 or greater, or 87 g-cm2 or greater. MOI is measured on a
model MOI-005-104 Moment of Inertia Instrument manufactured by Inertia
Dynamics of Collinsville, Conn. The instrument is connected to a PC for
communication via a COMM port and is driven by MOI Instrument Software
version #1.2.

[0110] When numerical lower limits and numerical upper limits are set
forth herein, it is contemplated that any combination of these values may
be used.

[0111] All patents, publications, test procedures, and other references
cited herein, including priority documents, are fully incorporated by
reference to the extent such disclosure is not inconsistent with this
invention and for all jurisdictions in which such incorporation is
permitted.

[0112] While the illustrative embodiments of the invention have been
described with particularity, it will be understood that various other
modifications will be apparent to and can be readily made by those of
ordinary skill in the art without departing from the spirit and scope of
the invention. Accordingly, it is not intended that the scope of the
claims appended hereto be limited to the examples and descriptions set
forth herein, but rather that the claims be construed as encompassing all
of the features of patentable novelty which reside in the present
invention, including all features which would be treated as equivalents
thereof by those of ordinary skill in the art to which the invention
pertains.